Hindu cosmology measures time in units that dwarf anything in ordinary reckoning — and it measures them with startling precision. The four yugas run 1,728,000 · 1,296,000 · 864,000 and 432,000 years, in the exact proportion 4 : 3 : 2 : 1, and above them stand the Manvantara, the Kalpa and the hundred-year life of Brahma. This guide gives the scriptural arithmetic from Manusmriti and the Puranas, explains the character and prescribed practice of each age, sets out where the tradition places the present moment, and answers the question the scheme always raises: why should time run downhill?
⏳ The Cycle at a Glance
Satya Yuga — 17,28,000 yrs · dharma on 4 legs · practice: meditation
Treta Yuga — 12,96,000 yrs · dharma on 3 legs · practice: sacrifice
Dvapara Yuga — 8,64,000 yrs · dharma on 2 legs · practice: worship
Kali Yuga — 4,32,000 yrs · dharma on 1 leg · practice: the divine name
One Mahayuga = 43,20,000 years · Kalpa = 1,000 Mahayugas = one
day of Brahma
Key sources: Manusmriti 1.68–71 · Vishnu Purana 1.3 · Bhagavata 3.11 ·
Mahabharata, Vana Parva
📑 Table of Contents
⏳ What the Yugas Are
Hindu cosmology does not treat time as a line running from a beginning to an end. It treats time as cyclical — an immense wheel turning through four ages that repeat without limit. The four ages are Satya (or Krita), Treta, Dvapara and Kali, and one full turn of the four is a Mahayuga or Chaturyuga.
The scheme is set out in several places, most systematically at Manusmriti 1.68–71, Vishnu Purana 1.3, Bhagavata Purana 3.11, and in the Mahabharata's Vana Parva, where Hanuman explains the ages to Bhima. The figures given in these sources agree.
📏 The key conversion
The yuga lengths are given in the texts as divine years, and one divine year equals 360 human years — a year of the gods being a day of ours. Every human- year figure below is the scriptural divine-year figure multiplied by 360. This is why the numbers are so precise: they are not estimates but arithmetic.
📊 The Four Ages and Their Exact Lengths
Each yuga has a main body plus a sandhya (dawn) and a sandhyamsha (twilight), each equal to one tenth of the main body. Manusmriti 1.69–71 states this explicitly, and it is why the totals are 4,800 rather than 4,000 divine years for Satya, and so on.
| Yuga | Main body | Sandhya + Sandhyamsha | Total (divine yrs) | Human years |
|---|---|---|---|---|
| Satya / Krita | 4,000 | 400 + 400 | 4,800 | 17,28,000 (1,728,000) |
| Treta | 3,000 | 300 + 300 | 3,600 | 12,96,000 (1,296,000) |
| Dvapara | 2,000 | 200 + 200 | 2,400 | 8,64,000 (864,000) |
| Kali | 1,000 | 100 + 100 | 1,200 | 4,32,000 (432,000) |
| Mahayuga (total) | 10,000 | 2,000 | 12,000 | 43,20,000 (4,320,000) |
💡 The ratio is the point
The four ages stand in the proportion 4 : 3 : 2 : 1. That ratio is the whole structure — everything else is that ratio scaled. Dharma is described in the same proportion: the Bhagavata Purana (1.17.24–25) pictures dharma as a bull standing on four legs in Satya Yuga, three in Treta, two in Dvapara and one in Kali. The bull does not fall; it simply has less to stand on.
🌞 Satya Yuga — The Age of Truth
1,728,000 years · dharma on four legs
Also called Krita Yuga — "the age that is done" — because nothing remains to be accomplished. The texts describe it as an age in which dharma is complete and needs no enforcement: there is no disease, no fear, no deceit and no division into contending groups. Human lifespan is given as very long, and the prescribed spiritual practice is dhyana — meditation — because nothing external is required and nothing obstructs it. There is said to be one Veda, undivided, and no need of temples or images, since the divine is not experienced as distant.
🔥 Treta Yuga — The Age of Sacrifice
1,296,000 years · dharma on three legs
A quarter of dharma is lost. The characteristic practice becomes yajna — sacrifice — because the divine now requires an intermediary act to approach. This is the age of the great kings and of ritual as the organising institution of society. Agriculture and settled kingship appear. The Ramayana is set in Treta Yuga, and the avataras of this age are traditionally given as Vamana, Parashurama and Rama.
⚔️ Dvapara Yuga — The Age of Worship
864,000 years · dharma on two legs
Half of dharma is gone; the world stands in balance between righteousness and its opposite, which is what dvapara — "the two-ish" — names. The characteristic practice is archana, temple worship. Disease and discontent enter. The single Veda is divided into four by Vyasa, because it can no longer be held whole. The Mahabharata is set at the close of this age, and Krishna's departure marks its end.
🌑 Kali Yuga — The Age of Contention
432,000 years · dharma on one leg
Named not for the goddess Kali but from kali, meaning strife or the losing throw of the dice. Three quarters of dharma are gone. The characteristic practice is nama-sankirtana — the recitation of the divine name — and the reason given is precisely the age's degradation: nothing more demanding can be sustained, so the requirement has been lowered. The classical descriptions are at Vishnu Purana 6.1 and Bhagavata Purana 12.2.
🌌 The Larger Cycles: Manvantara and Kalpa
The Mahayuga is only the smallest unit of the scheme. Above it:
| Unit | Composition | Human years |
|---|---|---|
| Mahayuga | The four yugas | 4,320,000 |
| Manvantara | 71 Mahayugas + sandhi; each presided over by a Manu | ≈ 306,720,000 |
| Kalpa (= 1 day of Brahma) | 1,000 Mahayugas = 14 Manvantaras + sandhis | 4,320,000,000 |
| Day + night of Brahma | 2 kalpas | 8,640,000,000 |
| Life of Brahma | 100 Brahma years | ≈ 311,040,000,000,000 |
At the end of Brahma's day, the worlds are withdrawn and rest through his night; at the end of his hundred years comes the maha-pralaya, the great dissolution, and the whole scheme begins again. The wheel has no first turn.
📍 Where We Are Now
The traditional reckoning of the present moment
- Kalpa: Shveta-Varaha Kalpa
- Manvantara: the seventh, Vaivasvata — presided over by Vaivasvata Manu, the Manu of the flood narrative
- Mahayuga: the 28th of this manvantara
- Yuga: Kali Yuga
- Epoch: Kali Yuga is traditionally reckoned to have begun in 3102 BCE, at the departure of Krishna — the date used by the Surya Siddhanta and by Aryabhata, and the basis of the Kali Ahargana count still used in panchanga calculation
- Elapsed: a little over 5,100 years of 432,000 — that is, roughly 1.2% of the age has passed
📉 Why the Ages Descend
A frequent question: why should time run downhill? The texts give a consistent answer, and it is not pessimism.
- Descent is structural, not moral. The yugas are not a punishment. They are the natural cooling of a cycle, as a day naturally becomes evening.
- The requirement descends with it. Each age is given a practice proportionate to what it can bear — meditation, then sacrifice, then worship, then simply the name. The texts are explicit that the last is the easiest.
- The cycle turns. Kali Yuga ends and Satya Yuga follows. The scheme has no final degradation because it has no final anything.
- The stated advantage of the worst age. Both the Vishnu Purana and the Bhagavata argue that Kali Yuga is the best age to be born in, because the ratio of result to effort is at its most favourable. What required a thousand years of tapas in Satya Yuga is said to be obtained in Kali by sincere recitation.
📌 A distinction worth keeping
The yuga scheme is a cosmological and moral framework given in the Puranas and the Dharmashastras. It is not presented in those texts as a geological or archaeological chronology, and this page does not treat it as one. Reading it as the tradition presents it — an account of how dharma stands, and what practice suits the age — is both more accurate and more useful than trying to map it onto a timeline of the physical past.
❓ Frequently Asked Questions
How long is each of the four yugas?
Satya Yuga is 1,728,000 human years, Treta Yuga 1,296,000, Dvapara Yuga 864,000 and Kali Yuga 432,000. Together they form one Mahayuga of 4,320,000 years. The scriptures give these figures in divine years, which are converted at 360 human years to one divine year.
Which yuga are we in now, and how much of it has passed?
We are in Kali Yuga, in the 28th Mahayuga of the seventh or Vaivasvata Manvantara. Kali Yuga is traditionally reckoned to have begun in 3102 BCE at the departure of Krishna, which means a little over 5,100 years of its 432,000 have elapsed — roughly 1.2 per cent of the age.
Why are the yugas in the ratio 4:3:2:1?
The ratio expresses the progressive diminishing of dharma. The Bhagavata Purana at 1.17.24–25 pictures dharma as a bull standing on four legs in Satya Yuga, three in Treta, two in Dvapara and one in Kali. The lengths of the ages follow the same proportion, so the structure of the scheme and its moral content are the same figure expressed twice.
What is a Kalpa and how long is one day of Brahma?
A Kalpa is one thousand Mahayugas, which is 4,320,000,000 human years, and it constitutes a single day of Brahma. His night is of equal length, so a full day and night is 8,640,000,000 years. Brahma's lifespan of a hundred such years works out to approximately 311.04 trillion human years, at the end of which comes the maha-pralaya.
What is the recommended spiritual practice for each yuga?
The texts assign a characteristic practice to each age: meditation (dhyana) in Satya Yuga, sacrifice (yajna) in Treta, temple worship (archana) in Dvapara, and recitation of the divine name (nama-sankirtana) in Kali. The progression is deliberate — each age is given a practice proportionate to what it can sustain, and the last is described as the easiest.
Is Kali Yuga the worst age to be born in?
The texts say the opposite. Both the Vishnu Purana and the Bhagavata Purana argue that Kali Yuga, while the most degraded age, is the best to be born in because the ratio of result to effort is at its most favourable. What required a thousand years of austerity in Satya Yuga is said to be obtained in Kali Yuga through sincere recitation of the divine name.
What is a sandhya and sandhyamsha in the yuga calculation?
Each yuga has a dawn period called sandhya and a twilight period called sandhyamsha, each equal to one tenth of the yuga's main body. Manusmriti 1.69–71 states this explicitly. It is why Satya Yuga totals 4,800 divine years rather than 4,000 — a main body of 4,000 plus 400 of sandhya and 400 of sandhyamsha.
🙏 Conclusion
The yuga scheme is one of the most distinctive things Hindu thought has produced: a model of time that is vast, exact, cyclical and — this is the part usually missed — ultimately consoling. The ages descend, but they descend on a wheel, and the descent is matched at every stage by a lowering of what is asked. A tradition that places us 5,100 years into a 432,000-year age is not telling its readers that the end is near. It is telling them that the scale is beyond calculation, that the present age asks very little, and that the little it asks is sufficient.
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